This invention relates generally to instrument probe assemblies, and more particularly to sealing instrument probe assemblies from leakage.
At least some known turbine engines include a compressor for compressing air which is suitably mixed with a fuel and channeled to a combustor wherein the mixture is ignited within a combustion chamber for generating hot combustion gases. A portion of the compressor discharge air is directed to a cavity surrounding the combustor for cooling the combustor liner. An operating temperature of the compressor discharge air is at least partially determinative of a rating and power capability of the engine. Accordingly, within at least some known engines the compressor discharge air temperature is monitored with a temperature probe.
At least some known temperature probes include a probe sensor that is inserted into position within the discharge air flow path from outside the engine casing. The probe sensor may extend through a plurality of walls to reach a predetermined position wherein the probe sensor is exposed to the compressor discharge air. For example, in at least some engines, the probe sensor may extend through a fan duct and a wall of the outer flow channel cavity of the engine. Although, the penetrations through the walls that allow installation between the temperature probe may be sealed to prevent leakage, differential thermal expansion of the walls may result in relative movement between the walls, thus causing the seals to leak. Leakage of relatively higher energy air from the outer flow channel cavity of the engine to the fan duct annulus and to an ambient area, and from the fan duct annulus to the ambient area may affect engine performance and engine component life.